MARESTE GAMMIARIDEAN AMPHIPODA 113 



6. All urosomites coalesced (fig. 13) kuriidae (p. 280) 



Urosomites separate 7 



7. Antennae and pereopods strongly spinose or setose, spines and setae long, 



epistome nasiform (fig. 11) dogielinotidae ^ (p. 207) 



Antennae and pereopods poorly spinose or setose (spines if numerous very 

 small), epistome rounded or truncate in front. 



(fig. 12) TALITROIDEA (p. 463) 



8. Lower lip lacking inner lobes, outer lobes obsolescent (fig. I73g), gnathopods 



small, chelate, slender, equal, sixth article elongate (figs. 173d, e). 



Didymocheila (incertae sedis) (p. 478) 



Lower lip with inner lobes and strong mandibular lobes, gnathopods not 



taking special form of figs. 173d, e 9 



9. Urosome depressed corophiidae (p. 184) 



Urosome not depressed . . . (exceptional) aoridae (p. 147) and isaeidae 



(p. 264) 



10. Mandibular palp present 11 



Mandibular palp absent 12 



11. Gnathopods subchelate, outer plates of maxilliped very small, inner obsolete. 



(fig. 14) pagetinidae 2 (p. 387) 

 Gnathopods chelate (fig. 15e) inner and outer plates of maxilliped well formed. 



(exceptional) sebidae (p. 435) 



12. Body cylindrical (fig. 87a), coxae small . . (fig. 8) eophliantidae (p. 209) 

 Body compressed (normal), coxae large, not splayed. 



Najna (Talitroidea) (p. 470) 



Body depressed, rugose, coxae splayed laterally, or if body not rugose pereon- 



ites laterally discontiguous (fig. 10) phliantidae (p. 405) 



' Metoediceros Schellenberg (1931) resembles this family but its epistome is unknown and its telson is 

 nearly a perfect, uncleft circle, whereas Dogielinotidae have a rectangular, cleft telson. Metoediceros is pres- 

 ently classified with the Oedicerotidae but it probably should form the type of a new family and is therefore 

 removed to "iacertae sedis." 



2 Urosomites 2-3 are presumed to be coalesced. 



SECTION F 



1. Body plan cylindrical (fig. 87a) 2 



Body plan compressed or depressed 3 



2. Palp of maxilla 1 larger than outer plate, inner lobes of maxilliped degraded. 



(fig. 9) COLOMASTIGIDAE (p. 182) 



Palp of maxilla 1 degraded, inner plates of maxilliped well developed, 

 separate (fig. 8) eophliantidae (p. 209) 



3. Mandibular molar of medium size, triturative (fig. 2/) 4 



Mandibular molar enormous, smooth (fig. 166d) . 



Jeddo (Synopiidae) (p. 461) 

 Mandibular molar evanescent or absent, lacking grinding ridges .... 6 



4. Uropod 3 with subequal rami (fig. 50). 



Sunamphitoe (Ampithoidae) (p. 145) 

 Uropod 3 with inner ramus reduced or absent 5 



5. Accessory flagellum absent (fig. 12) TALITROIDEA (p. 463) 



Accessory flagellum present (fig. 42) beaudettiidae (p. 166) 



6. Mouthparts from lateral view conically grouped below head, uropod 3 bi- 



ramous and well developed, coxae 1-4 compressed, elongate, forming lateral 

 shield, body compressed, smooth . . (fig. 4) stegocephalidae (p. 436) 



